With the expanding use of lightwave components for data transmission, optical component packages have been developed incorporating optical fibers and surface and channel waveguides. Placement, orientation and routing as well as the alignment and interconnection of the optical components in optoelectronic packages becomes more difficult where space and topography become more restricted.
The present invention is directed to providing efficient interconnects within an optical or electroptical package. Background art within this technology is described in the following references.
U.S. Pat. No. 4,432,600 issued Feb. 21, 1984 to Falco entitled "Method and Apparatus for Coupling at Least Two Optical Fibers by Means of a Holographic Lens" discloses a process of coupling optical fibers by means of a holographic lens, and an apparatus for carrying out this process. A holographic lens is recorded conventionally by utilization of a provisional hologram, by means of two monomodal optical fibers mounted by their respective end pieces in a block used to support the holographic lens. The block has bores, clearly defined in shape and position, into which are introduced the end pieces of monomodal fibers to effect recording of the holographic lens, and in which are fixed the end pieces of multimodal fibers to effect recording of the holographic lens, and in which are fixed the end pieces of multimodal fibers which are to be optically coupled after withdrawal of the monomodal fibers. The process and apparatus of the invention enables the speckling phenomenon, i.e., that of non-uniform distribution of light in the transmitted beams, to be suppressed, improving the efficiency of the holographic lens.
U.S. Pat. No. 4,756,590 issued Jul. 12, 1988 to Forrest et al. entitled "Optical Component Package" discloses an optical package including at least one electro-optical component aligned with at least one optical fiber. The electro-optical component is mounted on a surface which is essentially parallel to, but not coplanar with, the longitudinal axis of the fiber and light is coupled between the fiber and component by bending the light path. Electrical connection to the component is provided by conductors mounted over the same surface, thus producing a compact package. The invention is used preferably with arrays of components and fibers to eliminate the need for a vertical fanout to contact the components.
U.S. Pat. No. 4,945,400 issued Jul. 31, 1990 to Blonder et al. entitled "Subassembly for Optoelectronic Devices" describes a subassembly for use in packaging an optoelectronic device (e.g., LED or photodiode) that includes a semiconductor (e.g., silicon) base and lid having a variety of etched features (e.g., grooves, cavities, alignment detents) and metalization patterns (e.g., contacts, reflectors) which enable the device to be reliably and inexpensively mounted on the base and coupled to the fiber.
U.S. Pat. No. 5,026,131 issued Jun. 25, 1991 to Jannson et al. entitled "High Channel Density, Broad Bandwidth Wavelength Division Multiplexer with Highly Non-Uniform Bragg-Littrow Holographic Grating" discloses a wavelength division multiplexer/demultiplexer having optical path lengths between a fiber array and a Fourier transform lens, and between a dispersion grating and the lens equal to the focal length of the lens. The equal optical path lengths reduce losses due to angular acceptance mismatch in the multiplexer. Close orientation of the fiber array about the optical axis and the use of a holographic dispersion grating reduces other losses in the system. Multi-exposure holographic dispersion gratings enable the multiplexer/demultiplexer for extremely broad-band simultaneous transmission and reflection operation. Individual Bragg plane sets recorded in the grating are dedicated to and operate efficiently on discrete wavelength ranges. A volume Bragg vertically non-uniform holographic grating enables operation of the multiplexer or other devices that act on light waves according to wavelength over nearly the full usable 0.8-1.3 .mu.m wavelength range.
U.S. Pat. No. 5,056,881 issued Oct. 15, 1991 to Bowen et al. entitled "Collimated Laser Diode" teaches an optical source that comprises a laser light source for emitting light in a light path and at least one holographic optical element disposed in the light path; wherein the laser light source and the holographic optical element are integrated into a monolithic structure. The holographic optical element collimates emitted light, circularizes emitted light, compensates for optical source wavelength shifts, launches the emitted light so that it is efficiently coupled to an optical fiber, and/or isolates the laser light source from interfering reflected light. Since the optical source is disposed in a single monolithic structure and a discrete holographic optical element may perform five distinct functions, the optical sources are compact, commercially versatile and easy to handle.
U.S. Pat. No. 5,067,792 issued Nov. 26, 1991 to Lloyd entitled "Method and Apparatus for Interfacing of Holographic and Electronic Data" discloses an apparatus for interfacing holographic and electronic data that comprises an input/output port for the interfacing of a holographic wavefront interference pattern and an electronic array capable of producing digital electronic information from a holographic wavefront input and for converting electronic information into holographic information using optical fibers, sensors, and optical switches. In one embodiment a plurality of optical fibers having a small end and a large tapered end are operably combined with a plurality of optical sensors wherein each of said optical sensors provide a digital signal of 1 if lit and a digital signal of 0 if unlit.
U.S. Pat. No. 5,082,339 issued Jan. 21, 1992 to Linnebach entitled "Optical Read-Write Head with Diffraction Grating Structure" describes a holographic optical component and its use for reading the writing/reading heads. This application requires a minimum size and low weight for the holographic optical components. This is achieved in accordance with the invention by arranging a laser element and a grating structure, which is integrated on a waveguide layer and acts as a holographic optical system, on a large sized surface side of a flat carrier element such that a light beam of the laser element impinges directly on the grating structure and is so converted by the grating structure that it exits from the component.